A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-634-0322
NSN 6620-01-253-0374
NSN 5835-01-455-3380
NSN 7035-01-391-7470
NSN 2925-01-633-4048
NSN 5835-01-066-4419
NSN 6645-01-212-9474
NSN 5996-01-532-8764
NSN 5895-01-504-3746
NSN 5990-00-985-1334
NSN 5895-01-236-0132
NSN 6620-01-207-0667